The present invention relates to improvements in apparatus for severing running webs of paper, imitation cork or the like. More particularly, the invention relates to improvements in apparatus which can be utilized, for example, in filter tipping machines to subdivide webs of cigarette paper, imitation cork or other types of tipping paper into discrete uniting bands. Such uniting bands can be utilized in filter tipping machines to connect plain cigarettes of unit length or multiple unit length with filter plugs or filter mouthpieces of unit length or multiple unit length. Still more particularly, the invention relates to improvements in severing or subdividing apparatus of the type wherein the web which is to be subdivided into discrete sections or uniting bands is caused to advance between a rotary counterknife or anvil and a rotary knife carrier which is provided with one or more adjustable knives serving to cut across the running web during travel toward and through the nip of the counterknife and the knife carrier.
As a rule, the rotary knife carrier of a severing apparatus for running webs of tipping paper or the like is provided with several axially parallel grooves for reception of knife holders which, in turn, support the blades whose cutting edges sever the running web while moving past the rotary counterknife. The knives and/or their holders are adjustable individually so as to ensure that the cutting edge of each knife will actually contact the peripheral surface of the rotary counterknife in the course of a cutting or severing operation. Such adjustability of the knives ensures that the cutting edges will form clean cuts all the way across the running web, namely, from the one to the other marginal portion of the web. Reference may be had to the commonly owned U.S. Pat. No. 3,340,757 granted Sept. 12, 1967 to Willy Rudszinat. The patented apparatus utilizes knives which are pitovable on axially movable wedge-like adjusting elements so that any axial displacement of the adjusting elements results in radial displacement of the knives with reference to the axis of the knife carrier. Adjustability of the knives is desirable for several reasons, namely, for the aforediscussed reason that the cutting edges of all knives should actually contact the peripheral surface of the counterknife upon completion of a cut and also because the wear upon the cutting edges is quite pronounced so that it is necessary to intermittently move the knives radially outwardly to compensate for wear upon their cutting edges. As a rule, an adjustment is necessary after a certain period of continuous use, for example, upon completion of each eight-hour shift. Such cutting apparatus operate quite satisfactorily except that the adjustment of each and every knife upon completion of a shift or after elapse of another interval takes up a substantial amount of time. Moreover, it is often necessary to resort to highly accurate and sensitive calibrating or testing apparatus which must ascertain the magnitude of force or pressure with which the cutting edges of the orbiting knives engage the peripheral surface of the counterknife.